Method and device for ventilating or air-conditioning



1970 k. H. STEIGERWALD 3,492,934

METHOD AND DEVICE FOR VENTILATING 0R AIR-CONDITIONING Filed Feb. 13, 1968 z Sheet-Sheet 1 IN VENTUR 1970 K. H. STEIGERWALD 3,4

METHOD AND DEVICE FOR VENTILATING OR AIR-CONDITIONING Filed Feb. 15, 1968 2 Sheets-Sheet 2 NTDR E: 2i

BY. Ma

United States Patent 3,492,934 METHOD AND DEVICE FOR VENTILATING OR AIR-CONDITIONING Karl Heinz Steigerwald, 1a Haderunstrasse 8, Munich 55, Germany Filed Feb. 13, 1968, Ser. No. 705,145 Claims priority, application Germany, Feb. 14, 1967, St 26,490 Int. Cl. F24f 13/06 US. Cl. 9833 Claims ABSTRACT OF THE DISCLOSURE According to the present invention, gas flows serving for ventilation or air-condition of a room are conducted to or from said room through exchange areas in the form of walls having a great number of fine perforations distributed over a large area. In contrast to conventional fibrous or porous diffusers, the perforation channels of the invention are uniformly sized and distributed, they have no mutual interconnections and produce well-defined separate gas flows, the flow velocities of said partial gas flows being adjusted to a value which is sufficiently low to avoid draft phenomena, and a number of said partial flows being chosen so that a desired total flow is obtained.

The invention concerns a method and a device for ventilating or air-conditioning, wherein at least one gas flow serving the ventilation or air-conditioning is conducted to or from at least one exchange area of a room to be ventilated or air-conditioned.

With methods and devices of the kind indicated, it is generally difiicult to introduce sufficient amounts of gas, e.g. conditioned fresh air, into the room without causing draft phenomena. The same is true for the withdrawal of used air which is either effected in an uncontrolled manner through any openings of the room or through at least one separate outlet channel. In this connection, it is known to arrange diffusers of fibrous or porous material within the entrance or outlet openings of a gas flow serving for ventilation or air-conditioning. By these diffusers, a gas flow shall be uniformly distributed over the total cross-sectional area of the exchange area to thereby avoid the generation of draft phenomena. Diffusers of this kind, however, do not satisfactorily operate in this desired manner. Due to the irregular distribution and nonuniform sizes of the gas channels contained therein, the gas flow is in effect not uniformly distributed. Thus, for example, in such known diffusers which have a relatively low total flow resistance, a relatively high gas flow causing undesired draft particularly in proximity of the exchange area is present particularly in surface portions which are close to the associated connection conduit whereas only relatively small amounts of gas flow through the remaining surface portions of the diffuser. It is true that a somewhat more uniform distribution may be obtained by the use of a diffuser material of higher density; however, the flow resistance will then be higher, and the improvement of the uniformity is less than expected.

It is the object of the present invention to provide a method and device for ventilation or air-conditioning wherein a very uniform and to a great extent predeterminable distribution of the gas flow is obtained by simple means.

According to the invention, this object is attained by a method of the kind mentioned above wherein the gas flow is conducted to or from the exchange area in the form of a great number of separate partial flows distributed over said exchange area, the flow velocity in each of said partial flows being adjusted to a value which is sufficiently low to avoid draft phenomena, and the number of said partial flows being chosen so that a desired flow value is obtained.

A device according to the invention which solves the problem stated is characterized by at least one perforated wall arranged in the exchange area, said perforated wall forming an end wall of a flow channel for said gas flow and having perforation channels extending therethrough each of which generates a partial flow.

The measures according to the invention may be used for the supply to as Well as for the withdrawal of gas from the room to be ventilated or air-conditioned,

Preferably, at least partial flows per cm. are used, e.g. more than 1000 partial flows per cm.

Thus, in contrast to the known fibrous or porus diffusers wherein irregular and interconnected gas channels are present, the invention uses a great number of separate, well-defined partial flows, and it has been found that thereby the generation of draft phenomena is avoided to a great extent yet an intense ventilation or air-conditioning may be obtained. This is particularly important if the room to be ventilated or air-conditioned is relatively small, e.g. in vehicles or aircrafts, so that the distance between the exchange area and persons who are present in the room is necessarily small.

A further advantage over the known fibrous or porous diffusers resides in the fact that the surface of a perforated wall is smooth, clean and mechanically resistant so that protective covers are not necessary. Since relatively small wall thicknesses are suflicient if very fine perforation channels are used, the weight and the space requirements of walls perforated according to the invention are relatively low; the perforated walls may also be formed as foils which are particularly convenient in use. Also in contrast to known perforated walls having relatively large holes, the use of a great number of fine or very fine perforation channels or partial flows according to the invention results in a considerably more uniform distribution over the total exchange surface independently of the position of the associated flow conduit.

According to the invention, it is particularly advantageous to use perforated walls the perforation channels of wihch had been produced in a manner known per se by means of beamed raidiant energy, e.g. an electron beam. By means of beamed radiant energy, extraordinary fine throughbores can be produced very rapidly and in great numbers. In doing so, it is particularly advantageous that an amount of material corresponding to the volume of the perforation channel is actually withdrawn from the wall material, and so also wall materials may be used which have a tendency toward cold flow. Moreover, when using materials of this kind, perforation channels are obtained the Walls of which are solidified in the manner of a fuse crust.

Further features and advantages of the invention will become apparent from the following description of an example, taken in connection with the drawings.

FIG. 1 illustrates the invention in very schematic manner when applied to a room which is shown in crosssection.

FIG. 2 shows in a schematic sectional view, on an enlarged scale with respect to FIG. 1, a portion of a perforated wall according to the invention.

FIG. 3 illustrates schematically in a sectional view the structure and possibilities of attachment of wall elements according to the invention.

FIG. 4 shows in a schematic sectional view similar to FIG. 3 another embodiment of a wall element in accordance with the present invention.

FIG. 5 shows in a view similar to FIGS. 3 and 4, further embodiment of wall elements according to the present invention.

FIG. 6 illustrates several possibilities for the ventilation or air-conditioning of a living room.

FIG. 7 illustrates in a sectional view of possible application of the invention in an already present hot-air heating.

FIG. 1 shows as a typical example for a room 1 to be air-conditioned, a very schematical sectional view through the passenger cabin of an aircraft. Very schematically, two rows of seats 19 and 20 arranged on a floor 21, as well as baggage carriers 22 and 23 are illustrated. 24 indicates very schematically a conditioning unit which is arranged in the space between the cabin wall 26 and the floor 21. This conditioning unit supplies air of fresh air into a supply conduit 4, and withdraws used air from an outlet conduit 104. Within the wall 26, a perforated wall 3 is arranged in an exchange area 2. The wall 3 forms a border of the supply conduit 4 for the total inflow. The structure of the perforated wall may be seen in greater detail from the enlarged illustration of FIG. 2. There, it may be seen that the perforated wall 3 has perforation channels 5 extending therethrough. These channels are supplied from a common supply chamber 7 which forms part of the supply conduit 4, with the gas, normally conditioned air which is delivered from the conditioning unit 24. Thus, every perforation channel 5 generates a partial flow which enters the room 1 through the exchange area 2. Perferably, the perforation channels 5 are substantially parallel and are greater in length than in diameter.

The supply conduit 4 may be connected to the supply chamber 7 at any point thereof, e.g. in a small side of the supply channel according to FIG. 1, or, as shown in FIG. 2, via a connection 8 provided within the rear wall 27 of the supply chamber 7. The connection 8 may, for example, have the form of a threaded nipple having an exterior thread 28.

The gas inflow delivered by the conditioning unit 24 which may be attached to the wall 26 of the room 1 by attaching means 25, thus enters the room through the exchange area 2 in the form of a great number of separate partial flows which are distributed over a large area. According to the invention, in every partial inflow, the flow velocity is adjusted to a value which is sufiiciently low to avoid draft phenomena, and the number of the partial inflows are chosen in correspondence with the desired total inflow. With a given capacity of the conditioning unit 4 or a similar device delivering the gas inflow, the desired low values of the flow velocities can be obtained at will in the exchange area 2 by selecting the number and the diameter of the perforation channels 5 accordingly. In doing so, it is of advantage, in accordance with the invention, if the partial flows leave the exchange area in a substantially parallel relationship. According to the invention, the partial flows have preferably diameters below 0.5 mm. The surface density of the flow areas may be greater than 100 per cm. and even greater than 1000 per cm. If the cross-sectional area of the perforation channels and/or the driving pressure differential is selected sufficiently low, it is possible to distribute a desired gas inflow uniformly over a relatively great surface inspite of a high perforation density.

For the withdrawal of used air, either the normally present leak openings of the room to be ventilated or airconditioned may be utilized, or at least one gas outflow is withdrawn from the room in accordance with the invention through at least one perforated wall arranged in an outflow exchange area. This perforated wall forms a border of an outlet conduit for the total outflow and is traversed by perforation channels each of which conducts a partial outflow away. In the embodiment shown in FIG. 1, an outflow exchange area 102 is provided at a point of the room 1 lying opposite to the inflow exchange area 2. A perforated wall 103 is built into the outflow exchange area 102. The space behind the perforated wall is connected to an outlet conduit 104 which conducts the used air to the conditioning unit 24. The wall 103 may have a similar structure like the wall 3 so that the FIG. 2 may also be applied for the perforated wall 103 arranged in the outflow exchange area.

Like in the inflow exchange area 2, it is also possible in the outflow exchange area 102 to obtain, by choosing the number and the cross-sectional area of the perforation channels appropriately, in each partial outflow a flow velocity adjusted to a value which is sufliciently low to avoid draft phenomena. Of course, the number of the partial outflows is chosen in correspondence with the desired total outflow. With respect to the surface density and the sizes of the perforation channels, nearly the same conditions may be present in the outflow exchange area 102 as in the inflow exchange area 2. Again, by selecting corresponding low cross-sections and pressure differentials, a uniform distribution of the total outflow may be obtained arcoss a very large area. Preferably, partial outflows are used which have diameters below 0.5 mm.; for example, at least partial outflows per cm. and even more than 1000 partial outflows per cm? may be provided. The total cross-sectional area of the partial outflows withdrawn through a given surface area may amount to between approximately 5 and approximately 50% of this surface area. Preferably, the perforation channels extend substantially parallel and are greater in length than in diameter.

With perforated walls of plastic material, the danger exists when using conventional perforation methods wherein the perforation channels are pierced, that the channels are gradually closed again by a continuous back-flow of the material. Therefore, the device according to the present invention is preferably characterized by the fact that the amount of wall material corresponding to the volume of the perforation channels is taken out of the perforated wall. In perforations of this kind, a gradual clogging of the perforation channels by back-flowing wall material is practillay impossible.

According to the invention, it is particularly advantageous if the perforated wall 3, 103 forms a border of a hollow wall element 6 of the room to be ventilated or air-conditioned. Examples for such hollow wall elements according to the invention are shown in section in the FIGS. 3 to 5.

FIG. 3 shows in a sectional view two wall elements 6 lying side by side, wherein on the one side the border is formed by a perforated wall 3 with perforation channels 5. The wall elements 6 are hollow, and a connection 8 for a conduit is provided at their rear side to form a communication to the interior space 7. In the wall element 6 shown on the left side of FIG. 3, the connection 8 is provided with an extension 16 so that a closure plug 17 may be inserted conveniently toward an abutting position. The connections 8 are preferably formed as threaded nipples having an exterior thread 29.

In the embodiment of a hollow Wall element according to the invention which is shown in FIG. 4, the side of the wall element which faces the room 1 to be ventilaed or air-conditioned consists of a grate-like backing wall 10 which is overlied by the perforated wall in form of a foil 9. This foil may, e.g., be bonded or otherwise attached to the backing wall 10. Again, a connection 8 leading to the interior space 7 is provided.

According to the invention, a particularly useful structure is obtained if several wall elements each having a perforated wall are arranged side by side. An example therefore is illustrated in FIG. 3, and this figure as well as in FIGS. 4 and 5, wall elements according to the invention are shown which are provided with interengaging fitting portions 11, 12 so that the proper mutual position of the wall elements is automatically obtained when arranging the elements side -'by side. If it is desired to use several wall elements side by side for the same purpose, it may be appropriate to connect these wall elements not via exterior conduits between their connections 8 but, rather, to provide connection channels 13 in the side walls of the wall elements to connect the interior spaces of adjacent wall elements 6. Connection channels 13 of this kind are illustrated in FIG. 5. This figure further shows that alternatively also connection: channels 13 may be used which have an enlarging step 18 so that a closure plug like the plug 17 may again be inserted there into an abutting position if the respective connection channel 13 is not needed. This is particularly the case if adjacent wall elements are connected to different conduits, for example, to an inflow conduit and an outflow conduit, respectively. It has been found that in many cases a convenient ventilation is obtained if the wall elements, taken individually or in groups, are alternately connected to the inflow conduit and the outflow conduits, respectively. The wall elements are preferably provided with attaching means by which they may be mounted at any other parts and/ or among themselves. In FIG. 3, a throughbore 14 in the right wall element, and a threaded hole 15 in the left wall element are shown as examples for suchattaching means. Thus, by means of a bolt inserted through the bore 14 and threaded into the thread 15, a rigid connection of the two wall elements and/ or an attachment of the wall elements at any other structure parts (not shown) may be effected.

FIG. 3 illustrates several possibilities in the ventilation or air-conditioning of a living room. For example an inflow exchange area from which finely distributed warm air enters the room, may be provided below a wall 30 in a wall 42 in the form of a flat wall element 31 which is mounted upon the wall 42 or is partially or totally sinked into this wall. As shown in FIG. 6, very great inflow exchange areas are possible so that draft phenomena may be avoided effectively. The structure of the wall elements 31 may, for example, correspond to one of the embodiments shown in the FIGS. 2 to 5; it is important that the front side facing the room is formed by a perforated wall the structure of which is similar like that of the walls shown in the FIGS. 2 to 5. The connection of the wall element 31 to a hot-air supply conduit is not shown in FIG. 6.

Further, FIG. 6 illustrates that also other walls of a room, for example the walls 32a and 32b, may be provided with inflow or outflow exchange areas 33 and 34, respectively, wherein also wall elements having perforated walls according to the invention may be provided to supply or withdraw air. If, for example, as in FIG. 6, a large inflow exchange area 31 for the entrance of warm air is provided below a window, the further wall elements 33 and 34 which are shown in FIG. 6 and may have a structure similar to the embodiments of FIGS. 2 to 5, may be connected to outlet conduits so that a uniformly distributed air stream is obtained between the inflow exchange area 31 and two outflow exchange areas 33 and 34. Of course, also the wall element 33 may serve the supply of heated air whereas the wall element 34 may serve the withdrawal of used air. Because of the flat structure of the wall elements according to the invention, which elements may moreover be sinked in the walls of the room, and because of the very low exit velocities of the gas flows leaving or entering the perforated walls, the effectiveness of the measures according to the invention will not appreciably be affected if furnitures are positioned at only a small distance in front of the perforated walls.

When applying wall elements of great surface area in living rooms in accordance with the example of FIG. 6, it is important to provide for sufficient sound absorption and/or eventually also a suflicient heat insulation. Therefore, and in accordance with the invention, the perforated walls may be backed by a gas-pervious layer which has sound-absorbing and/or heat-insulating properties and may consist, for example, by a layer of foamed material. Generally, the gas perviousness of the layer will be greater than the gas previousness of the perforated wall. Of course, one could also imagine to take advantage of the porosity of the layer to help in the purpose of finely distributing the gas inflow or outflow. Therefore, the perforation of the gas-permeable wall may be correspondingly more coarse particularly in cases where the gaspervious layer is of very fine porosity.

FIG. 7 illustrates another embodiment of a wall element according to the invention which is particularly suited for the application in already installed hot-air heatings. If, for example, according to the schematic illustration of FIG. 7, a hot-air channel opens into a wall 35 of a room 1 to be ventilated or air-conditioned, the wall element 37 of in FIG. 7 may simply be introduced into the hot-air channel. This wall element has a connection which is not, like in FIGS. 2 to 4, formed as a threaded nipple but as a stud 38 fitting into the hot-air channel 36. The main portion 39 which has a substantially larger cross-section than the stud 38, sits flatly upon the wall 35 when the wall element is introduced. The front side of the wall element is formed by a perforated wall 41 in accordance with the invention, which wall is backed by a gaspervious layer 40 of foamed material. The layer 40 chiefly serves the purpose to prevent sound transfer from the hotair channel into the room 1.

A great variety of materials may be selected for the perforated walls according to the invention. For example, perforated walls made of metal, plastic, metal-plastic combinations, and even ceramic materials may be used. Practically, every material is suited which is adapted to be perforated at reasonable cost and shows no tendency of gradual clogging of the generated perforation channels by cold flow. According to the invention, it is particularly advantageous if the perforated wall consists of a material which had been perforated by means of beamed radiant energy. By means of energy beams, for example, laser or electron beams, almost all materials can be exactly and very finely perforated at extraordinarily high speeds. In the case of plastics, a particular advantage is obtained in that perforation channels produced by energy beams have a crust-like solidified wall.

The terms ventilating and air-conditioning as used herein shall relate to all processes wherein gaseous media are introduced into or withdrawn from a room for the purpose of influencing a gaseous atmosphere. For example, this may apply to the supply of heated air for purposes of heating, to the supply of fresh air, chilled air or air which is enriched with oxygen or other gases. Further, one may also think of applications wherein the gas supplied or withdrawn is not air.

Further embodiments are possible without leaving the scope of invention.

I claim:

1. A device for ventilating or air-conditioning a room by means of at least one gas flow conducted to or from said room through at least one exchange area, said exchange area being defined by a plurality of hollow wall elements arranged side by side in a wall of the room, each of said wall elements having a hollow interior and a perforated wall between said hollow interior and said room, a conduit for a gas connected to open into said perforated wall having a plurality of fine perforation channels extending therethrough from said hollow interior to said room, and each of said perforation channels being adapted to conduct a partial flow of a gas between said hollow interior and said room, the number of said perforation channels being chosen so as to obtain a desired total flow.

2. The device of claim 1, characterized in that said wall elements or groups thereof are alternately connected to a supply conduit and an outlet conduit, respectively.

3. The device of claim 1, wherein said wall elements have interengaging fitting portions.

4. The device of claim 1, wherein at least some of said wall elements have communicating channels adapted to communicate the interior spaces of adjacent wall elements.

5. The device of claim 4, wherein said communicating channels are selectively closable.

6. The device of claim 1, wherein said perforated wall is backed by a gas-pervious layer.

7. The device of claim 1, wherein said perforated wall consists of material which has been perforated by means of radiant energy such as an electron beam.

8. The device of claim 7 wherein said perforated Wall has more than 100 perforation channels per cm. extending therethrough.

9. The device of claim 7 wherein said perforated wall has the form of a foil overlying a grate-like backing wall.

10. The device of claim 1 wherein said perforated wall consists of perforated material in which each perforation has been formed by removing an amount of the material corresponding to the volume of said perforation.

References Cited UNITED STATES PATENTS LLOYD L. KING, Primary Examiner U.S. Cl. X.R. 98-10, 104 

